A specialised shotcrete system for refractory and mining applications

摘要

A unique chemical system has been developed for use in shotcreting in which high viscosity cementitious materials may be more easily pumped and sprayed. This system involves the incorporation of an organic foaming agent in the mixture to facilitate easier pumping and a viscosifying additive introduced at the nozzle that imparts thixotropy to the mix. The use of large volumes of compressed air at the nozzle and proper nozzle selection ensure that the foam incorporated within the mix is dissipated when the mix impacts and adheres to the target surface. Although originally developed for refractory applications, the system is applicable to mixes that have previously been considered unpumpable either due to dilatancy of the mixture or to the inherent qualities of low water content mixes. Testing to date with refractory concrete demonstrates that the system imparts no deleterious effects to the final properties of these materials.